Frame unit for bicycle and method of manufacturing the same

ABSTRACT

A frame unit for a bicycle may include a left frame body in which a part of a seat tube, a part of a frame, and a left stay are integrally formed, a right frame body in which a part of the seat tube, a part of the frame, and a right stay are integrally formed, and a reinforcing panel disposed within the left and right frame bodies, wherein the left frame body and the right frame body may be coupled so as to integrally form the head tube, the seat tube, and the frame.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority of Korean Patent ApplicationNumber ** filed 10-2013-0097429 filed Aug. 16, 2013, the entire contentsof which application is incorporated herein for all purposes by thisreference.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a frame unit for a bicycle and a methodof manufacturing the same, and more particularly, to a frame unit for abicycle which includes a head tube, a seat tube, a frame, and left andright stays and a method of manufacturing the same.

2. Description of Related Art

In general, a frame unit for a bicycle is a constituent component thatforms an overall structure of a bicycle, and manufactured by mutuallyjoining constituent components such as a head tube, a seat tube, aframe, and left and right stays.

Regarding the frame unit for a bicycle, allowing flexibility to providevarious designs and secure rigidity for safety are core factors, and tothis end, the respective manufacturers actively conduct researches ondevelopment of technologies, process methods, materials, and the like.

Recently, in order to implement various designs and secure rigidity forsafety, materials such as aluminum, chromium-molybdenum steel, carbon,and titanium are used instead of a high tensile steel material that isgenerally used.

FIG. 1 is a configuration diagram of a frame unit for a bicycleaccording to the related art.

Referring to FIG. 1, a frame unit 100 for a bicycle of the related artincludes a head tube 101, a seat tube 103, an upper frame 105, a lowerframe 107, and upper and lower stays 109 and 111 disposed at both sides.

A steering shaft to which a steering handle is connected is installed onthe head tube 101, and a seat pipe connected to a seat is installed onthe seat tube 103.

The upper and lower frames 105 and 107 connect and support the head tube101 and the seat tube 103.

Rear ends of both the upper and lower stays 109 and 111 are connected toeach other so as to form a rotating body fork 113 to which a rear wheelis mounted.

A front end of the lower stay 111 is connected to a pedal assembly 115that is configured at a lower end of the seat tube 103.

Meanwhile, the frame unit 100 for a bicycle mostly is provided withreinforce elements to joining portions, such as between the head tube101 and the upper and lower frames 105 and 107; between the seat tube103 and the upper and lower frames 105 and 107 and so on for securingrigidity for safety.

Meanwhile, the frame unit 100 for a bicycle mostly includes both theupper frame 105 and the lower frame 107, but in some cases, only asingle frame, that is, only the upper frame 105 may be applied betweenthe head tube 101 and the seat tube 103.

However, according to the frame unit 100 for a bicycle of the relatedart, which has the aforementioned configuration, when the head tube 101,the seat tube 103, the upper frame 105, the lower frame 107, and theupper and lower stays 109 and 111 are joined to each other by a weldingprocess, residual stress due to welding heat is distributed to joiningportions. Particularly, impact loads are directly applied when thebicycle runs, thereby causing a serious problem with respect to safetysuch as cracks or damage occurring at the periphery of the joiningportions.

Since the process of welding the joining portions is manually performed,an inferiority rate is high because there is a difference in weldingquality in accordance with skill of workers and working environment, andthereby, there are drawbacks in that an excessive working time isrequired and productivity deteriorates.

Since the reinforce elements are provided to an exterior of the frameunit 100, thereby, design freedom of the frame unit 100 are poor, andweld beads protrude at the joining portions between the respectivecomponents, thereby causing deterioration in overall aestheticappearance because of heterogeneity between the respective components.

The weld beads protruding at the joining portions between the frame unit100 and the reinforce elements cause excessive management for weldingquality and deterioration in productivity.

The information disclosed in this Background section is only forenhancement of understanding of the general background of the inventionand should not be taken as an acknowledgement or any form of suggestionthat this information forms the prior art already known to a personskilled in the art.

BRIEF SUMMARY

Various aspects of the present invention provide for a frame unit for abicycle and a method of manufacturing the same having advantages ofimproving rigidity and design quality.

Various aspects of the present invention provide for a frame unit for abicycle that may include a left frame body in which a part of a seattube, a part of a frame, and a left stay are integrally formed, a rightframe body in which a part of the seat tube, a part of the frame, and aright stay are integrally formed, and a reinforcing panel disposedwithin the left and right frame bodies, wherein the left frame body andthe right frame body may be coupled so as to integrally form the headtube, the seat tube, and the frame.

The reinforcing panels may be installed between the head tube and theframe, between the seat tube and the frame, on a portion of the left andright stays where a rear wheel is installed, and inside a pedal assemblyon which a pedal is installed, respectively.

The reinforcing panels may be joined together when the left and rightframe bodies are joined in a state in which the reinforcing panels arefitted or temporarily joined to the left and right frame bodies.

On the reinforcing panel, a plurality of reinforcing beads may beformed.

The reinforcing beads may protrude so as to intersect inward and outwardfrom the reinforcing panel.

The left frame body and the right frame body may be coupled by a weldingmethod.

Various aspects of the present invention provide for a method ofmanufacturing a frame unit for a bicycle that may include press-forminga left frame body in which a part of a head tube where a steering shaftis mounted thereto, a part of a seat tube where a seat pipe is mountedthereto, a part of a frame configured to integrally connect the headtube and the seat tube and form a body of a bicycle, and a left stay areintegrally formed, press-forming a right frame body in which a part ofthe head tube, a part of the seat tube, and a right stay are integrallyformed, disposing a reinforcing panel within the left right and rightframe body, and coupling the left frame body and the right frame bodyeach other along edges of the left and right frame bodies.

The reinforcing panels may be installed between the head tube and theframe, between the seat tube and the frame, on a portion of the bothstays where a rear wheel is installed, and inside a pedal assembly onwhich a pedal is installed, and thereafter, joined together with theleft and right frame bodies.

The reinforcing panels may be joined together with the left and rightframe bodies in a state in which the reinforcing panels are fitted ortemporarily joined to the left and right frame bodies.

The reinforcing panels may be are formed together with reinforcing beadsthat protrude so as to intersect each other inward and outward.

Various aspects of the present invention provide for a bicycle includinga head tube, a seat tube, a frame, a pedal assembly and a left and rightstays that are integrally formed with the main frame without a joiningportion such that residual stress due to welding heat at a joiningportion in the related art may be removed, and a factor, which causesjoint rigidity deterioration due to the residual stress, may beeliminated.

Accordingly, rigidity and durability between the head tube and the framewith respect to an impact load transmitted from a road surface and afatigue load of the frame unit per se are firmly maintained, therebypreventing damage such as cracks, and securing safety.

The left and right frame bodies, which form the frame unit for abicycle, are integrally formed, thereby making the entire exteriorappearance of the frame unit for a bicycle be aesthetically attractive.

In addition, welding work is performed along edges of the left and rightframe bodies when the left and right frame bodies are joined, such thatwelding processes may be automated, working times may be reduced due tothe automation, and welding quality and productivity may be improved.

Since the reinforcing panel is mounted within the left and right framebodies for enhancing the rigidity, and the reinforcing panel is notexposed to the outside, thus heterogeneity between the frame and thereinforcing panel may be reduced and overall aesthetic appearance may beimproved. Also, design freedom for the frame may be enhanced.

Since the reinforcing panel are not to be welded from outside, excessivemanagement for welding quality with naked eyes may be reduced, andproductivity may be enhanced.

The left and right frame bodies are joined in a state in which areinforcing panel is locally installed inside the left and right framebodies such that rigidity of the frame 1 may be enhanced, and totalweight may be reduced.

The methods and apparatuses of the present invention have other featuresand advantages which will be apparent from or are set forth in moredetail in the accompanying drawings, which are incorporated herein, andthe following Detailed Description, which together serve to explaincertain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a configuration diagram of a frame unit for a bicycleaccording to the related art.

FIG. 2 is a side view of an exemplary frame unit for a bicycle accordingto the present invention.

FIG. 3 is a perspective view of an exemplary frame unit for a bicycleaccording to the present invention.

FIG. 4 is an exploded perspective view of an exemplary frame unit for abicycle according to the present invention.

FIG. 5 is an enlarged perspective view showing a reinforcing panelprovided to an exemplary frame unit for a bicycle according to thepresent invention.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of thepresent invention(s), examples of which are illustrated in theaccompanying drawings and described below. While the invention(s) willbe described in conjunction with exemplary embodiments, it will beunderstood that present description is not intended to limit theinvention(s) to those exemplary embodiments. On the contrary, theinvention(s) is/are intended to cover not only the exemplaryembodiments, but also various alternatives, modifications, equivalentsand other embodiments, which may be included within the spirit and scopeof the invention as defined by the appended claims.

A part irrelevant to the description will be omitted to clearly describethe present invention, and the same or similar elements will bedesignated by the same reference numerals throughout the specification.

The size and thickness of each component illustrated in the drawings arearbitrarily shown for understanding and ease of description, but thepresent invention is not limited thereto. Thicknesses of severalportions and regions are enlarged for clear expressions.

Further, in the following detailed description, names of constituents,which are in the same relationship, are divided into “the first”, “thesecond”, and the like, but the present invention is not limited to theorder in the following description.

Throughout the specification and the claims, unless explicitly describedto the contrary, the word “comprise” and variations such as “comprises”or “comprising” will be understood to imply the inclusion of statedelements but not the exclusion of any other elements.

In addition, “unit”, “means”, “part”, “member”, or the like, which isdescribed in the specification, means a unit of a comprehensiveconfiguration that performs at least one function or operation.

FIG. 2 is a side view of a frame unit for a bicycle according to variousembodiments of the present invention, FIG. 3 is a perspective view of aframe unit for a bicycle according to various embodiments of the presentinvention, and FIG. 4 is an exploded perspective view of a frame unitfor a bicycle according to various embodiments of the present invention.

Referring to FIGS. 2 to 4, a frame unit 1 for a bicycle according tovarious embodiments of the present invention includes a head tube 3, aseat tube 5, a frame 7, a pedal assembly 9, and left and right stays 11and 11 a.

A steering shaft 15 to which a handle 13 is mounted is installed to thehead tube 3, and a front wheel 19 is installed by a fork 17 configuredat a lower side of the steering shaft 15.

A seat 23 is installed to the seat tube 5 by a seat pipe 21.

The frame 7 may include an upper extension frame 25 configured tointegrally connect the head tube 3 and the seat tube 5, and a lowerextension frame 27 integrally connected to the pedal assembly 9, andforms a body of a bicycle 29. One will appreciate that such integralcomponents may be monolithically formed.

The left and right stays 11 and 11 a include an upper stay 31, and alower stay 33, respectively, and rear ends of both the upper stays 31and rear ends of both the lower stays 33 are connected to each other soas to form a rotating body fork 37 to which a rear wheel 35 is mounted.

Further, front ends of both the upper stays 31 are connected to the seattube 5, and front ends of both the lower stays 33 are connected to thepedal assembly 9 configured at a lower side of the seat tube 5.

The pedal assembly 9 may be formed to protrude downward at a lower sidebetween the frame 7 and both the lower stays 33, and a pedal 9 a, whichis connected to the rear wheel 35 by a chain 39, is installed on thepedal assembly 9.

Here, the head tube 3, the seat tube 5, the frame 7, the pedal assembly9, and the left and right stays 11 and 11 a are formed by a left framebody 41 and a right frame body 43, which are integrally formed. One willappreciate that such integral components may be monolithically formed.

Further, the left and right frame bodies 41 and 43 are joined alongedges thereof so as to form an overall configuration of the frame unit 1for a bicycle.

The left and right frame bodies 41 and 43 are joined to each other by awelding method, and in this case, the welding method may be an arcwelding method or the like.

FIG. 5 is an enlarged perspective view showing a reinforcing panelprovided to a frame unit for a bicycle according to various embodimentsof the present invention.

Referring to FIG. 5, the left and right frame bodies 41 and 43 arejoined in a state in which a reinforcing panel 45 is locally installedinside the left and right frame bodies 41 and 43 such that an overallconfiguration of the frame 1 for a bicycle may be formed.

That is, the reinforcing panel 45 may be installed at a portion whererigidity is needed, that is, as illustrated in FIG. 5, between the headtube 3 and the frame 7. And also the reinforcing panels 27 may also beinstalled between the seat tube 5 and the frame 7, to the rotating bodyfork 37 to which the rear wheel 35 is mounted, to inside the pedalassembly 9 and so on.

Further, the reinforcing panels 45 are joined together when the left andright frame bodies 41 and 43 are joined to each other, in a state inwhich the reinforcing panels 45 are fitted to both inner sides of theleft and right frame bodies 41 and 43, respectively, or in a state inwhich the reinforcing panels 45 are fitted into and then temporarilyjoined to the inner sides of the left and right frame bodies 41 and 43.

Here, grooves in which the reinforcing panels 45 are disposed may beformed at both the inner sides of the left and right frame bodies 41 and43, and the reinforcing panels 45 may be fitted or temporarily joined tothe grooves.

Meanwhile, the reinforcing panel 45 has a plurality of reinforcing beads47 that is formed to protrude. The reinforcing beads 47 protrude so asto intersect inward and outward along an up and down direction of thereinforcing panel 45, thereby improving rigidity of the reinforcingpanel 45 per se.

According to the frame unit 1 for a bicycle according to variousembodiments of the present invention, which has the aforementionedconfiguration, the head tube 3, the seat tube 5, the frame 7, the pedalassembly 9 and the left and right stays 11 and 11 a are integrallyformed with the main frame 7 without a joining portion such thatresidual stress due to welding heat at a joining portion in the relatedart may be removed, and a factor, which causes joint rigiditydeterioration due to the residual stress, may be eliminated. One willappreciate that such integral components may be monolithically formed.

In addition, an occurrence of a safety accident due to cracks and damagewhich have occurred at the joining portion is reduced, and rigidity anddurability between the head tube 3 and the frame 7 with respect to animpact load transmitted from a road surface and a fatigue load of theframe unit per se are firmly maintained.

Further, the left and right frame bodies 41 and 43, which form the frameunit 1 for a bicycle, are integrally formed, thereby making the entireexterior appearance of the frame unit 1 for a bicycle be aestheticallyattractive. One will appreciate that such integral components may bemonolithically formed.

In addition, welding beads, which occur when the left and right framebodies 41 and 43 are joined, are not directly exposed to a surface, suchthat an influence on the entire exterior appearance design of the frameunit 1 for a bicycle is minimized.

In addition, welding work is performed along edges of the left and rightframe bodies 41 and 43 when the left and right frame bodies 41 and 43are joined, such that welding processes may be automated, working timesmay be reduced due to the automation, and welding quality andproductivity may be improved.

Since the reinforcing panel 45 is mounted within the left and rightframe bodies 41 and 43 for enhancing the rigidity, and the reinforcingpanel 45 is not exposed to the outside, thus heterogeneity between theframe 1 and the reinforcing panel 45 may be reduced and overallaesthetic appearance may be improved. Also, design freedom for the frame1 may be enhanced.

The left and right frame bodies 41 and 43 are joined in a state in whicha reinforcing panel 45 is locally installed inside the left and rightframe bodies 41 and 43 such that rigidity of the frame 1 may beenhanced, and total weight may be reduced.

Hereinafter, a method of manufacturing the frame unit 1 for a bicycleaccording to various embodiments of the present invention, which hasbeen described above, will be described with reference to FIGS. 3 to 5.

First, the seat tube 5, the frame 7, the pedal assembly 9, and the leftand right stays 11 and 11 a are integrally formed, and the left andright frame bodies 41 and 43, which are symmetric to each other, arepress-formed, respectively.

Thereafter, the left and right frame bodies 41 and 43 formed by a pressare joined to each other by welding along edges of the left and rightframe bodies 41 and 43, and manufactured as the frame unit 1 for abicycle, as illustrated in FIG. 3.

Meanwhile, as illustrated in FIG. 5, the reinforcing panels 45 arelocally installed inside the left and right frame bodies 41 and 43before the left and right frame bodies 41 and 43 are joined, andthereafter, the left and right frame bodies 41 and 43 may be joinedalong the edges of the left and right frame bodies 41 and 43.

The reinforcing panels 45 are installed at portions where rigidity isneeded, for example, between the head tube 3 and the frame 7, betweenthe seat tube 5 and the frame 7, on the portion of the rotating bodyfork of the both stays 11 where the rear wheel 35 is installed, andinside the pedal assembly 9, respectively, and thereafter, thereinforcing panels 45 are joined together when the left and right framebodies 41 and 43 are joined.

In this case, the reinforcing panels 45 may be joined together with theleft and right frame bodies 41 and 43 in a state in which thereinforcing panels 45 are fitted or temporarily joined to the left andright frame bodies 41 and 43, and the plurality of reinforcing beads 47,which protrudes so as to intersect each other inward and outward, mayalso be formed.

For convenience in explanation and accurate definition in the appendedclaims, the terms upper or lower, front or rear, and etc. are used todescribe features of the exemplary embodiments with reference to thepositions of such features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of thepresent invention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteachings. The exemplary embodiments were chosen and described in orderto explain certain principles of the invention and their practicalapplication, to thereby enable others skilled in the art to make andutilize various exemplary embodiments of the present invention, as wellas various alternatives and modifications thereof. It is intended thatthe scope of the invention be defined by the Claims appended hereto andtheir equivalents.

What is claimed is:
 1. A frame unit for a bicycle comprising: a leftframe body in which a part of a seat tube, a part of a frame, and a leftstay are integrally formed; a right frame body in which a part of theseat tube, a part of the frame, and a right stay are integrally formed;and a reinforcing panel disposed within the left and right frame bodies;wherein the left frame body and the right frame body are coupled so asto integrally form the head tube, the seat tube, and the frame.
 2. Theframe unit of claim 1, wherein the reinforcing panels are installedbetween the head tube and the frame, between the seat tube and theframe, on a portion of the left and right stays where a rear wheel isinstalled, and inside a pedal assembly on which a pedal is installed,respectively.
 3. The frame unit of claim 2, wherein the reinforcingpanels are joined together when the left and right frame bodies arejoined in a state in which the reinforcing panels are fitted ortemporarily joined to the left and right frame bodies.
 4. The frame unitof claim 3, wherein a plurality of reinforcing beads are formed on thereinforcing panel.
 5. The frame unit of claim 4, wherein the reinforcingbeads protrude so as to intersect inward and outward from thereinforcing panel.
 6. The frame unit of claim 1, wherein the left framebody and the right frame body are welded together.
 7. A method ofmanufacturing a frame unit for a bicycle comprising: press-forming aleft frame body in which a part of a head tube configured to support asteering shaft, a part of a seat tube configured to mount a seat pipe, apart of a frame configured to integrally connect the head tube and theseat tube and form a body of a bicycle, and a left stay are integrallyformed; press-forming a right frame body in which a part of the headtube, a part of the seat tube, and a right stay are integrally formed;disposing a reinforcing panel within the left right and right framebody; and coupling the left frame body and the right frame body eachother along edges of the left and right frame bodies.
 8. The method ofclaim 7, wherein the reinforcing panels are installed between the headtube and the frame, between the seat tube and the frame, on a portion ofthe both stays where a rear wheel is installed, and inside a pedalassembly on which a pedal is installed, and thereafter, joined togetherwith the left and right frame bodies.
 9. The method of claim 8, whereinthe reinforcing panels are joined together with the left and right framebodies in a state in which the reinforcing panels are fitted ortemporarily joined to the left and right frame bodies.
 10. The method ofclaim 7, wherein the reinforcing panels are formed together withreinforcing beads that protrude so as to intersect each other inward andoutward.